Apparatus for projection

ABSTRACT

An apparatus for projection capable of projecting light on a built-in transmission type screen or on a wall screen as desired. The apparatus has a door that may be opened and a movable mirror. The door is opened when a film is projected on the wall screen and closed when the film is projected on the built-in transmission type screen. The door and the movable mirror are operatively connected such that the movable mirror is positioned to direct the projected light to the outside when the door is closed. The apparatus also has three legs for the adjustment of the projection angle.

United States Patent 1191 Okano Apr. 30, 1974 APPARATUS FOR PROJECTION [75] Inventor: Takeshi Okano, Nishinomiya, Japan [73] Assignee: Fuji Shashin Film Kabushiki Kaisha,

Ashigarakami-gun, Kanagawa-ken, Japan [22] Filed: May 4, 1971 [21] Appl. No.: 140,156

3,279,109 10/1966 Whittum 353/98 3,136,207 6/1964 Flad 3,391,979 7/1968 Lessler..... 2,617,328 1 H1952 Stableford 353/72 Primary Examiner-Louis R. Prince Assistant Examiner-A. Jason Mirabito Attorney, Agent, or FirmStevens, Davis, Miller & Mosher [57] ABSTRACT An apparatus for projection capable of projecting light on a built-in transmission type screen or on a wall screen as desired. The apparatus has a door that may be opened and a movable mirror. The door is opened when a film is projected on the wall screen and closed when the film is projected on the'built-in transmission type screen. The door and the movable mirror are operatively connected such that the movable mirror is [5 References Cited positioned to direct the projected light to the outside UNITED STATES PATENTS when the door is closed. The apparatus also has three legs for the adjustment of the projection angle. 2,473,736 6/1949 Stern 353/71 2,495,528 1/1950 Langan 353/77 7 Claims, 4 Drawing Figures 1 '7 I l7 l0) PAYENFEAPR 30 B974 SHEET 1 BF 2 H IO APPARATUS FOR PROJECTION BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, numeral 1 designates a housing This invention relates to an apparatus for projection of the projection apparatus according to the present inwhich is capable of projecting light on a built-in transmission type screen as well as on a wall-screen, and more particularly to an apparatus for projection which comprises two mirrors of which one is movable, and a door that may be opened. The apparatus is capable of projection on the built-in transmission type screen through said mirrors and also on the wall screen when said movable mirror is rotated and said door is opened.

Apparatus for projection capable of projecting light selectively on a built-in transmission type screen or on a wall screen have been well known. However, such prior art apparatus almost without exception are complicated in construction and require a cumbersome operation. Furthermore, projection apparatus are normally provided with means for adjusting the angle of projection, but in the prior art apparatus of the type described above, the adjustment of the angle of projection has been troublesome.

SUMMARY OF THE INVENTION An object of the present invention is to simplify the construction of the projection apparatus of the type which is capable of projecting light selectively on a built-in transmission type screen or on a wall screen.

Another object of the invention is to simplify the operation of the projection apparatus of the type described, so that the direction of projection may be changed by a single operation.

Still another object of the invention is to facilitate the adjustment of the angle of projection in the projection apparatus of the type described.

In order to attain the objects set forth above, according to one aspect of the invention the projection apparatus includes a stationary mirror and a movable mirror, so that the direction of projection may be changed by rotating said movable mirror.

According to another aspect of the invention, the movable mirror and a door for a wall screen projection window are operatively connected, so the direction of projection may be changed simply by opening or closing said door.

According to still another aspect of the invention, the projection apparatus is provided with three height adjusting legs, so that when said legs have once been set in the positions selected under a specific condition, the angle of projection may be adjusted simply by adjusting only one of said legs, regardless of the direction of projection.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view showing an embodiment of the projection apparatus according to the present invention;

FIG. 2 is a plan view, similar to FIG. 1, of another embodiment of the projection apparatus with the door being closed;

FIG. 3 is a plan view of the embodiment shown in FIG. 2, with the door being opened; and

FIG. 4 is a perspective view showing the essential portion of the embodiment of FIG. 2.

vention, which is composed of a top wall not shown, a bottom wall 10 parallel to said top wall, and vertical wall 11 extending between the top and bottom walls. The vertical wall 11 is provided with a transmission type screen 2 and a door 3 that may be opened. The door 3 is hinged to the vertical wall 11 of the housing 1 at one end 30 thereof and pivotable between a closed position (indicated by the solid line) and an open position (indicated by the broken line). Inside the housing 1 are disposed a projector 4, a movable-mirror 5 and a stationary mirror 6. The movable mirror 5 is pivotable about a vertical axis 50 and takes two positions, i.e., a position (indicated by the solid line) to reflect the projected light from the projector 4 towards the stationary mirror 6 and a position (indicated by the broken line) to reflect the projected light towards the door 3. The stationary mirror 6 receives the projected light reflected by the movable mirror 5 and reflects the same towards a built-in transmission type screen 2 to form an image on said screen.

Numerals 7, 8, 9 designate height-adjusting legs provided on the underside of the bottom wall 10 of the housing 1. The positions of these legs 7, 8, 9 are such that the angle of projection can be adjusted only by moving one of the legs, when the projected light is projected in either direction. Namely, in the embodiment of FIG. 1 the straight line 7-8 connecting the legs 7 and 8 with each other is at right angles to the optical axis A of the projected light proceeding towards a wall screen and the straight line 8-9 connecting the legs 8 and 9 with each other is parallel to the built-in screen 2.

In the apparatus described above, when the built-in screen 2 is to be used, the height of the leg 7 is adjusted to incline the built-in screen at an angle suitable for the viewers. The adjustment only of the height of the leg 7 causes the angle of elevation of the built-in screen to be changed but does not cause the same to be inclined in a lateral direction and hence does not cause the projected image to be inclined in a lateral direction. Thus, the built-in screen can be simply adjusted at an angle perpendicular to the line of vision of the viewers, to facilitate the observation of the viewers. In this case, the door 3 is preferably held in the closed position to obtain a clear picture.

When the wall screen is to be used, on the other hand, the door3 is opened and the movable mirror 5 is rotated to the position indicated by the broken line. In this case, the angle of elevation of the optical axis of the projected light can be adjusted by changing the height of the leg 9. In the adjustment of the angle of elevation, the optical axis pivots about the line connecting the legs 7 and 8 with each other but the image projected on the wall screen is not inclined laterally.

In the foregoing description, the leg 8 need not necessarily be adjustable but the adjustment of the leg 8 becomes necessary when the apparatus is not mounted on a horizontal plane, to adjust the lateral inclination of the apparatus. However, once the lateral inclination of the apparatus has been adjusted, the subsequent adjustment of the angle of inclination can be achieved by the manipulation of only one leg. It will be obvious that auxiliary legs may be provided in addition to the three legs mentioned above, to extend the respective legs subsequent to the adjustment.

It will be understood that, if the movable mirror and the door 3 are operatively connected with each other in the projection apparatus of the invention described above, it will be possible to change the direction of the projection light from the built-in screen 2 to the wall screen, by the single operation of opening the door. I

Such an arrangement is exemplified in FIGS. 2 4. In this embodiment of the invention, the same or similar parts as those in the preceding embodiment are indicated by the same numerals.

A movable mirror 5 is retained by retainer members 51, 51 at the upper and lower sides of one end thereof, and said retainer members are pivotally mounted on a vertical pin 50 fixed on a bottom wall of a housing 1. Also pivotally mounted on the vertical pin 50 are members 31, 31 which retain a door 3. As best shown in FIG. 4, the movable mirror retainer members 51, 51 are provided with a connecting pin 32 in parallel relation with the pin 50, which extends through the door retainer members 31, 31 to associate the rotation of said door 3 with the rotation of said movable mirror 5. The movable mirror 5 has magnetic elements 52, 53 fixed on portions of the both sides thereof. On the bottom wall 10 of the housing 1 are provided a positioning magnet 12 to hold the movable mirror 5 in a position to reflect the projected light towards a stationary mirror 6 and a positioning magnet 13 to hold the same in a position to reflect the projected light towards the door 3. Numeral 54 designates a coil spring to bias the movable mirror 5 in a clockwise direction as viewed in FIG. 2 (in a direction to close the door 3), said coil spring being disposed around the pin 50 with one end anchored to the retainer member 51.

With the construction described above, when it is desired to project the light on a built-in screen 2, the door 3 is held in the closed position and the movable mirror 5 is held in a predetermined position with the magnetic element 52 on the back side thereof being magnetically attracted by the positioning magnet 12. The light from a projector 4 is projected on the built-in screen 2 via the movable mirror 5 and the stationary mirror 6 to form a picture image on said screen.

On the other hand, when it is desired to project the light on the wall screen, the door 3 is opened. In this case, the movable mirror 5 operatively connected to the door 3 through the connecting pin 32 is also caused to make a pivotal movement about the pin 50 and to be disengaged from the positioning magnet 12. When the door 3 has been opened to a predetermined angular position, the magnetic element 53 on the front side of the movable mirror 5 is attracted by the magnetic force of the positioning magnet 13, and thus the movable mirror 5 is set in a predetermined position. The light from the projector 4 is reflected on the movable mirror 5 towards the outside of the housing 1 and forms a picture image on the wall screen.

Now, if the direction of the projected light is desired to be changed from the wall screen to the built-in screen 2, the door 3 is closed, whereby the movable mirror 5 operatively connected to said door 3 through the connecting pin 32 is disengaged from the positioning magnet 13 and caused to make a pivotal movement. Since the door 3 is in loose engagement with the connecting pin 32, the movable mirror 5 comes to stop immediately before the positioning magnet 12. Thereafter, the movable mirror 5 is brought into the predetermined position under the biasing force of the coil spring 54 and the magnetic force of the positioning magnet 12 attracting the magnetic element 52 on the back side of said movable mirror. Thus, the light from the projector 4 is projected on the built-in screen 2 via the movable mirror 5 and the stationary mirror 6.

I claim:

1. An apparatus for projection comprising a housing having substantially parallel top and bottom walls and a vertical wall extending between said top and bottom walls, a transmission type screen provided at a first portion of the vertical wall of said housing, a door, provided at a second portion of the vertical wall of said housing, said second portion having an opening which may be closed by said door, a projector disposed within said housing, a stationary mirror disposed within said housing, and a movable mirror disposed within said housing and pivotable about a vertical pin to two positions to selectively direct the projection of light from said projector towards said stationary mirror in one position or to said opening in the other position, said stationary mirror being located at such a position to reflect the projected light reflected from said movable mirror in said one position towards said screen.

2. An apparatus for projection according to claim 1, wherein said movable mirror and said door are operatively connected with each other, and said door is held closed when said movable mirror is located in said one position to reflect the projected light towards said stationary mirror and is held open when said movable mirror is in the other position to reflect the projected light towards said opening.

3. An apparatus for projection according to claim 2, wherein said movable mirror and said door are pivotally mounted on a common pin.

4. An apparatus for projection according to claim 2, wherein a magnetic element is provided on each side of said movable mirror, while two positioning magnets are provided on the bottom wall of the housing to magnetically attract said magnetic elements respectively, whereby the movable mirror can be positioned at the two positions of said two magnets.

5. An apparatus for projection according to claim 4, wherein said movable mirror is constantly springbiased inwardly.

6. An apparatus for projection according to claim 3, wherein a coil spring is provided on said pin to constantly bias said movable mirror inwardly.

7. An apparatus for projection according to claim 1, wherein said housing is provided with at least three height adjusting legs at such locations that two of the three lines connecting said legs with each other respectively extend at right angles to the optical axis from the stationary mirror towards the transmission type screen and the optical axis from the movable mirror towards the opening. 

1. An apparatus for projection comprising a housing having substantially parallel top and bottom walls and a vertical wall extending between said top and bottom walls, a transmission type screen provided at a first portion of the vertical wall of said housing, a door, provided at a second portion of the vertical wall of said housing, said second portion having an Opening which may be closed by said door, a projector disposed within said housing, a stationary mirror disposed within said housing, and a movable mirror disposed within said housing and pivotable about a vertical pin to two positions to selectively direct the projection of light from said projector towards said stationary mirror in one position or to said opening in the other position, said stationary mirror being located at such a position to reflect the projected light reflected from said movable mirror in said one position towards said screen.
 2. An apparatus for projection according to claim 1, wherein said movable mirror and said door are operatively connected with each other, and said door is held closed when said movable mirror is located in said one position to reflect the projected light towards said stationary mirror and is held open when said movable mirror is in the other position to reflect the projected light towards said opening.
 3. An apparatus for projection according to claim 2, wherein said movable mirror and said door are pivotally mounted on a common pin.
 4. An apparatus for projection according to claim 2, wherein a magnetic element is provided on each side of said movable mirror, while two positioning magnets are provided on the bottom wall of the housing to magnetically attract said magnetic elements respectively, whereby the movable mirror can be positioned at the two positions of said two magnets.
 5. An apparatus for projection according to claim 4, wherein said movable mirror is constantly spring-biased inwardly.
 6. An apparatus for projection according to claim 3, wherein a coil spring is provided on said pin to constantly bias said movable mirror inwardly.
 7. An apparatus for projection according to claim 1, wherein said housing is provided with at least three height adjusting legs at such locations that two of the three lines connecting said legs with each other respectively extend at right angles to the optical axis from the stationary mirror towards the transmission type screen and the optical axis from the movable mirror towards the opening. 